[time-nuts] Minicircuits SYPD-1

[Attila Kinali]

Hoi Jerry,

On Tue, 18 Dec 2018 23:18:42 -0800
jerry <jerry at hanler.com> wrote:

> I'm playing around with various methods of collecting data for
> oscillator testing and would like to try the loose PLL which
> requires a phase detector (PD).  

I guess you are looking more into phase noise than stability?

> I'm testing an AD8302 but that has a flat spot around 176 to 180 degrees.

All phase detectors exhibit non-linearity in some form or other.
If you get all the way to +/-176° with good linearity, then be
happy. If you need more than that, then you have to either use
two phase detectors that are driven with a reference that is 90°
apart, or you have to digitize the signal and do the same in digital.

> One of the papers I read recommended the subject PD but it is out of
> stock everywhere, including the subs. One Minicircuits PD is in stock but
> pricey.  I can try a double balanced mixer like the SBL or TUF series (which
> I have on hand) but I thought maybe someone on the list has the subject PD
> they dont need. If so, please send me a note.

There is a decent alternative: Use two transformers and 4 2N2222 to
do your own mixer. The quality of it, according to NIST[1] is pretty
good. I assume that any other NPN transistor of similar make-up will
also do and lead to same/similar performance.

You might also want to have a look at Enrico's Mixer Tutorial[2]

> I'm slowly gathering parts for Riley's small Dual Mixer Time Difference
> test kit but it will take some time which I'm unfortunately running out
> of due to mild Parkinsons getting in the way of SMD soldering. I've used
> my HP 5371a in the past but it sounds like a jet engine.  I recently
> ordered a TICC as well.  By the time I'm done I probably will have
> purchased more than a commercial  product, ha!

Jürg Kögel did a redesign of the Riley DMTD earlier this year,
which looks very nice. And the measurements I've seen are very
impressive (it's on par with the best state of the art I am aware of).
So you might want to contact him and see whether he has some board left.

			Attila Kinali


[1] "Residual PM Noise Evaluation of Radio Frequecny Mixers"
by Barnes, Hati, Nelson, Howe, 2011
https://doi.org/10.1109/FCS.2011.5977868
http://time.kinali.ch/mixers/residual_pm_noise_evaluation_of_radio_frequency_mixers-2011-barnes_hati_nelson_howe-05977868.pdf

[2] "Tutorial on the double-balanced mixer"
by Enrico Rubiola, 2006
http://arxiv.org/abs/physics/0608211
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